Determining optimal trial size using sequential analysis

When characterising typical human movement profiles, the optimal number of trials analysed for each participant should ensure a stable mean. Sequential analysis is one method able to establish the number of trials to stability by assessing a moving point mean against a set bandwidth. As the total trial number determining this bandwidth is selected arbitrarily, the effect of applying different total trial numbers on the results of sequential analysis was investigated. Twenty participants performed 30 trials of overarm throwing, and sequential analyses were applied to three dimensional (3-D) kinematic data over 10, 20 and 30 trial numbers. We found a total of 20 to be the preferred trial number for sequential analyses. Erroneous results were produced consistently by 10 trial number groups, while moving point means were statistically unchanged after the 10th trial. Subsequently, sequential analyses were applied to 20 trials to establish trials to stability in discrete and time series elements of the 3-D kinematic data. The results suggest that a trial size between 13 and 17 provides stable means for overarm throwing kinematics.     

Potentiation of delayed matching with variable delays

In a delayed matching-to-sample procedure, pigeons chose a comparison stimulus that matched a sample stimulus presented earlier in the trial. The duration of the delay between sample-stimulus presentation and comparison-stimulus presentation was either varied over five values within each session or held constant within each session but varied over five blocks of sessions. Accuracy of matching to sample was higher overall with variable delays than with delays fixed within sessions. The result indicates that remembering depends on the temporal context provided by delay intervals.     

Professionalism and Intensification in Teaching: a case study of ‘care’ in teachers’ work

This paper reports a research project in teachers’ work in one secondary school. It takes a labour process perspective to examine how localized notions of professionalism act to both enable and disable teachers in their struggle to exercise control over their work. For the teachers in this study an ‘ethic of care’ appears to inform their practice and relationships. Professionalism as care plays a contradictory role in these teachers’ working lives, at the same time providing the motivation, commitment and conditions that result in the intensification and control of their work.